High speed tape recorder



Aug. 22, 1933. 1.. HJWEBB' 1,923,403

HIGH SPEED TAPE RECORDER Filed Feb. 12', 1931 INVENTOR 5 LAWRENCE H.WEBB

ATTORNEY I Patented Aug. 22, 1933 HIGH SPEED TAPE RECORDER Lawrence B. Webb, London, England, assignor to International Standard Electric Corporation, New York, N. ware Y., a Corporation of Dela- Application February 12, 1931, Serial No. 515,237,

and in Great Britain March 12, 1930 12 Claim.

This invention relates to tape recording apparatus more particularly for use in fire alarm or like systems wherein code impulses are sent from a warning point to a central station.

It is the object of the invention to increase the speed of signalling between warning points and a central station and to provide improved means at the central station for recording the signals. This increase of speed and recording of signals admits of several stations being connected on the same signalling line without providing the usual nonin'terference facilities therefor. According to one feature of the invention in a signalling system in which coded signals consist of signal impulses separated by spacing signals, a tape recording mechanism is "provided with means adapted to respond to each signal impulse to effect one recording operation on a tape, and to feed the tape one step, and to respond to each spacing signal to effect the feeding of the tape one or more steps without effecting any recording operation.

Another feature of the invention is a tape recorder. for a signalling system in which signal impulses consist of current breaks in a circuit over which current is normally flowing and in which means is provided which in response to each signal break impulse effects a record on said tape and in response to a spacing break feeds said tape without making any record.

According to another feature I provide a tape recorder for use in a system in which signal impulses consist of current breaks in a circuit over which current is normally flowing, in which a magnet is provided for punching a signal hole in a tape and for feeding the latter at each signal impulse the magnet being provided with in-" terrupter contacts over which it is operated during spacing signals to advance the tape without punching signal holes.

These and other features of the invention will be better appreciated from a consideration of the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 shows a plan view of a punching apparatus in which P is a punching magnet, PS

is an interposer magnet, and PC and C0 are two relays which control the operation of the punch magnet P and the punch spacer magnet PS.

Fig. 2 shows a section taken along the line A, B, C, D in Fig. l. v

Figs. 3 and 4 represent different modifications of the invention and show circuit arrangements incorporating the apparatus in Fig. 1.

Fig. 5 shows graphs representing the line 0 1 rents of the circuit arrangements shown in Figs. 3 and 4. The graph above the aero line 00 rep resents the line current of ,the arrangement shown in Fig. 3 whilst the graph below the zero line represents the line current of that shown in Fig. 4. Horizontal lines from the points X and Y represent the normal current values in the line.

Referring to Figs. land 2 the punch magnet shaft PMS has at one end an armature which is 765 operated upon by the punch magnet P, whilst fixed at its other end is a bell crank lever one limb of which forms a hammer H which through the medium of the punch interposer PUS is adapted to strike the punch PU. Attached to the other limb of this bell crank lever is a pawl PA which under the control of the spring S is adapted to engage with the star feed wheel SFW. a

The p'unch interposer PUS is operated by t e interposer magnet PS so as to be inserted be tween the hammer H and the punch PU. Normally without the insertion of the lever PUS the hammer H will .not strike the punch PU.

The punch PU pierces the tape T which. is fed through the machine by the rotation of the star feed wheel SFW- the teeth of which engage the holes in the centre of the tape. These feed holes may be punched by an additional punch TP which is struck at each actuation; of the hammer H.

The operation of the arrangement is as follows, when a marking signal arrives the interposer magnet PS isfirst energized to interpose the interposer PUS betweenthe hammer H and p the punch PU. After this has been accomplished the punch magnet P is operated so that the punch is struck by the hammer through the medium ,of the interposer therebypiercing. the tape to record the signal. I

When the punch magnet operated the pawl PA was made to engage with the succeeding itooth in the star feed wheel SFW so that when the armature of the punch magnet retracts the star feed wheel rotates and carries the tape T 10) with it.

When a spacing signal is received the punching magnet will alone be operated and the fpunch PU will not be struck by the hammer. However, seeing that the star feed wheel SFW 0 =will be rotated the tape will be advanced.

i As the tape is advanced after the reception of a signal an auxiliary punch TP can be arranged'so that each time a signal is received the hammer H strikes the auxiliary punch to 19 pierce the feed holes in the tape. By this method the tape need not be pierced with feed holes prior to being placed in the machine, and

therefore complicated drawing arrangements are dispensed with.

Referring now to the current diagrams shown in Fig. 5 fire alarm or like circuit arrangements are such that a current normally flows in the line circuit to provide a degree of supervision thereon. The-transmission of an impulse consists of a break in this current, but before a second impulse can be transmitted the circuit must be made again. Calls are arranged as a number of impulses of equal duration broken by spaces, and from a general point of view it is immaterial ,whether these spaces occur at periods of current or of no current providing that all are the same. However, both arrangemerits are hereinafter described. A complete alarm call may consist of a code of two or more digits broken up by one or more spaces and any of the digits may consist of up to nine in number. The particular code shown in Fig. 5 consists of three digits comprising impulse trains of 2, Sand 1 broken up by spaces a, b and c. In the graph shown above the zero line 00 the space consists of a no current interval in the circuit forming a prolongation of the last normal impulse break. Whilst in the graph below the broken line the space comprises a lengthened current interval between the digital trains.

In the upper graph the no current interval a, b or c, which is used for a spacing signal, between the digits-is formed integral with a no current interval representing a normal signal impulse. By this, method the utmost time economy is effected in the transmission of the code.

The operation of the circuit arrangement shown in Fig. 3 will now be described.

Relay L is a fast operating type of relay, whilst relays CO and PC may be of any ordinary type. P is the punch magnet and PS is the interposer magnet. The contact springs 10 and 11 are associated with the punch magnet P and are so arranged that .normally the contacts 10 are closed. but when the magnet is operated the contacts 10 open and the contacts 11 close.

The relay L is normally energized by the continuous current in the line, but relapses immediately a break occurs at an alarm giving point. At contact 12 of relay L the following circuit is closed for\the relay PC: ground, contact 12 of relay L, conductor 13, winding of relay PC to battery 14 and ground. At the same time the following circuit is prepared for the interposer magnet PS, the latter interposing the interposer lever in between the punch and hammer as heretofore described: ground, contact 12 of relay L, contact 15 of relay C0 through the winding of magnet PS to battery 16 and ground. At contact 17 of relay PC the following circuits are closed for the punch magnet P through its interrupter springs and contacts of relay CO in parallel: ground, battery 18, contact 1'1 of relay PC, conductor 19, windings of punch magnet P, conductor 20, contact 10 of magnet P to ground, and at the same time from conductor 20 over conductor 21 through closed contact 23 of relay CO and back through conductor 22 to ground.

The punch magnet P operates and causes the perforation of the tape, and simultaneously opens and closes the contacts 10 and 11 respectively, whereupon relay CO operates over a circuit from ground through contact 11, conductor ,24, winding of relay CO to battery 25 and ground and locks over its contacts 26 to ground at contact 12 of relay L.

Relay CO at its contacts 23 opens the circuit of the punch magnet P and at its contacts 15 opens the circuit of the interposer magnet PS and the interposer is thereupon withdrawn from its position between the punch and the hammer.

If by this time the relay L has been re-energized contact 12 will be opened and relays CO and PC will relapse and the process is repeated when relay L is again de-energized.

If, however, the line relay L is allowed to remain de-energized for more than unit time (as occurs at spaces a, b or c in the upper graph of Fig. 5) both relays C0 and PC will remain of the interposer magnet only one punch hole is recorded in the tape every time that L is energized and it delays the vibration of the punch magnet when relay CO is de-energized, but when energized allows the punch magnet P to vibrate under its own interrupter contacts 10,105

and therefore the punch magnet is allowed to I operate exceedingly fast. In this manner therefore the recording of the signals is comparatively slow whilst the spacing of the tape is comparatively fast.

The above method of code transmission requires specially designed impulse transmitters for each station so that the spacing signals between the digits occur at the required intervals.

It is the usual practice to provide .an impulse code wheel which has been cut with specially long' recesses at required intervals to produce this signal.

According to the ,embodiment of the invention about to be described the spacing signal is formed of a lengthened current impulse in the line circuit, and therefore this permits standard impulse wheels to be used at each station, each of which has the teeth masked to produce the correct interdigital code spacing.

Referring now to Fig. 4 in this arrangement, as heretofore explained with reference to Fig. 5, it is arranged that the interval between the code trains comprise a prolonged current impulse,

and this impulse causes the advance of the tape without perforating after a train or after a signal has been ceased Relays L and A are of the quick responding type and are normally permanently operated.

The interposer magnet PS' besides causing the insertion of the interposer also controls by means of contact 27, contact springs 28 which control the operation of the punch magnet P.

The relay R. maybe made slow to operate and release in any well known manner.

When the relay L is de-energized in response to a signal a circuit is closed for the interposer magnet P'S at contact 30 of relay L which inserts the interposer between the punch and the hammer and thenclosesthe circuit of the magnet operates and causes the recording of the signal and at the same time opens its interrupter springs 28.

When the signal ceases the relay L is reenergized, and the interposer magnet PS' deenergized, releasing magnet P. I

on the first release of relay L the circuit for relay A normally closed at contact 29 of relay L was opened and that relay relapsed closingthe circuit for the relay R which through its slow release feature remains operated during the whole of the code signal. The operating circuit for relay R is as follows: side of battery 31, conductor. 32, winding of relay R, conductor 38, contact 37 of relay A and conductor 35 to side of battery 31.

The relays L, A and the punch magnet P operate as heretofore described in response to impulses succeeding'the first impulse of a train forming part of the code signal. During the long circuit closure (a, b ore of lower graph of Fig. 5) representing a space between the impulse trains, the circuit for the slow. release relay R is opened at contact 37 of relay A but the relay R being slow to release remains operated and a circuit is closed for the punch magnet P via its interrupter springs 28 and operated contacts of relays A and R as follows: side of battery 31, conductor 32, contion that such mechanisms can be operated at great speed and therefore where several stations exist on the same signalling line it is highly improbable that two or more stations willsignal simultaneously as-to cause mutilated signals. Therefore the non-interference devices usually providedto overcome the possibility of such mutilations are entirely dispensed with.

Also although the recording mechanism is described as being associated with one signal-. ling line it may be easily arranged that the apparatus is common to a plurality of such lines, It may also be arranged that several recording mechanisms are common to a plurality of lines, and picked up in sequence or by station discrimination.

It will be understood that although the invention is described as applied to a fire alarm system, it may be applied to any type of signalling system such as police signalling systems, where a high speed of operation and recording of signals is required.

What is claimed is:

1. In a tape recording mechanism and in combination, a pawl and ratchet mechanism for stepping the tape, a magnet for operating said stepping mechanism, interrupter contacts operatively associated with said magnet, and means for placing said magnet under the control of said contacts whereby the speed of the stepping mechanism is altered.

2. In a tape recording mechanism responsive to impulse signals and to spacing signals;

means for stepping the tape and relay means for controlling said stepping mechanism characterized in that it is differentially responsive to impulse signals and spacing signals.

3. In a signalling system in which code signals consist of trains of signal impulses separated by spacing signals, a tape recording mechanism comprising means for advancing the tape a single step in response to each received signal impulse and 'means for advancing the tape a plurality of steps in response .to each spacing signal.

4. In a signalling system in which signal impulses and spacing signals consist of equal current breaks in a circuit over which current is normally flowing, a tape recording mechanism comprising a pawl and ratchet mechanism for feeding a recording tape, a magnet responsive to the received signal impulses for operating said mechanism and relay means for altering the speed of the feeding mechanism in response to the spacing signals.-

5. A signalling system in which signal impulses and spacing signals. consist of equal cur rent breaks in a circuit over which current is normally flowing, comprising a tape, a tape stepping mechanism, means for punching the tape, a relay responsive to said signals for operating said stepping mechanism and said punch, and

relay means for so controlling said last men-- which is operated during a signal impulse and.

is maintained during a spacing signal to close the circuit for the magnet operating the tape stepping mechanism.

7. In a signalling system in which signal impulses consist of current breaks in a circuit over which current is normally flowing, a tape recording mechanism comprising tape stepping mechanism for advancing the tape, means for punching holes in the tape, a magnet for operating both the tape stepping mechanism and the punching means in response to received signal impulses and interrupter contacts for said magnet over which it is operated during spacing signals to advance the tape at increased speed and without punching signal holes.

8. In a tape recording mechanism and in combination, a tape, tape stepping mechanism for advancing the tape, a punch for perforating asignal hole in the tape, a punch for perforating the last mentioned means to perforate the tape with one signal hole and a plurality of feed holes and to advance the tape a corresponding number of steps in response to a prolonged impulse representing both a signal impulse and a spacing impulse. v

9. In a signalling system in which trains of signal impulses are separated by spacing signals, a tape recording mechanism, comprising a tape, tape stepping mechanism for advancing the tape, means for perforating a signal hole and a feed hole in the tape and for feeding the tape one step in response to each received signal impulse, and means operable in conjunction with the last mentioned means for perforating a plurality of feed holes in said tape and for feeding the tape a corresponding number of steps in response to a spacing signal separating said groups of signalimpulses, without perforating any signal holes in the tape. a

10. In a tape recording mechanism, a pawl and ratchet mechanism for stepping the tape, a punch for perforating said tape, a punch magnet for operating both the stepping mechanism and the punch, an interposer magnet for controlling the reaction between the punch magnet and the punch, a line relay for controlling the interposer magnet in accordance with received signals, a plurality of interrupter contacts associated with the punch magnet, a relay operable to place said interrupter contacts in the operating circuit of said punch magnet whereby the speed of said tape stepping mechanism is altered.

11. In a tape recording mechanism and in combination, a pawl and ratchet mechanism for stepping the tape, a punch for perforating the 'tape, a punch magnet for operating both the stepping mechanism and the punch, an interposer magnet for controlling the reaction between the punch magnet and the punch, a line relay for controlling the interposer magnet in accordance with received signals, a relay operable under control of the line relay to operate the punch magnet, a relay operable under the joint control of the line relay and punch magnet to disconnect the interposer magnet after it has operated, interrupter means operated by the punch magnet, contact means under the control of said last mentioned relay for placing the interrupter means in the operating circuit of the punch magnet when the line relay remains deenergized for a predetermined length of time, to speed up the operation of said stepping mechanism.

12. In a tape recording mechanism and in combination, a pawl and ratchet mechanism for stepping the tape, a punch for perforating the tape, a punch magnet for operating both the stepping mechanism and the punch, an interposer magnet for controlling the reaction between the punch magnet and the punch, a line relay for controlling the interposer magnet in accordance with received signals, a relay operable by and concurrently with the line relay, 2. slow acting relay operable under the control of said last mentioned relay, interrupter contacts operated by the punch ---,magnet and in series therewith and contacts of the last two mentioned relays whereby on the reenergization of the line relay the punch magnet operates through its interrupter contacts to speed up the operation of said stepping mechanism.

LAWRENCE H. WEBB. 

